1. A gear shifting control device for a hybrid vehicle comprising: an automated manual transmission which transmits a rotation of an input shaft adapted to be rotated by an engine torque outputted from an engine mounted on the hybrid vehicle to an output shaft rotatably connected to a drive wheel of the vehicle by changing a speed of the rotation from one speed change ratio to another speed change ratio when an engine rotation speed of the engine goes over each speed change performance line prepared per each speed change ratio for a plurality of speed change stages; a clutch for engaging the output shaft of the engine with the input shaft of the automated manual transmission or disengaging the output shaft of the engine from the input shaft of the automated manual transmission and controlling a clutch torque transmitted to the input shaft of the automated manual transmission from the output shaft of the engine under an engagement state therebetween to be a target clutch torque by operation of a clutch actuator; a clutch torque—operating amount memory portion for memorizing a corresponding relationship between a clutch actuator operating amount of the clutch actuator which controls the clutch torque of the clutch and the clutch torque; a clutch control portion for controlling the clutch torque to the target clutch torque by obtaining the clutch actuator operating amount of the clutch actuator which corresponds to a predetermined target clutch torque from the clutch torque-operating amount memory portion and operating the clutch actuator by the clutch actuator operating amount; an engine rotation speed detecting portion for detecting the engine rotation speed of the engine; an engine output control operating amount detecting portion for detecting an engine operating amount of an engine output control portion for controlling an output of the engine; an engine torque detecting portion for calculating an engine torque from the engine operating amount of the engine output control portion detected by the engine output control operating amount detecting portion and the engine rotation speed detected by the engine rotation speed detecting portion based on a relationship between the engine rotation speed and the engine torque at each engine operating amount of the engine output control portion; a presumed clutch torque calculating portion for calculating a presumed clutch torque by subtracting an inertia torque which is obtained by multiplying a rotation inertia moment with an acceleration speed of the engine rotation speed from the engine torque calculated from the engine output control operating amount and the engine rotation speed by the engine torque detecting portion when the clutch control portion operates the clutch actuator to operate by a clutch actuator operating amount corresponding to the target clutch torque; a corresponding relationship correcting portion for correcting a corresponding relationship between the clutch actuator operating amount memorized in the clutch torque—operating amount memory portion and the clutch torque by learning the relationship between the presumed clutch torque calculated by the presumed clutch torque calculating portion and the clutch actuator operating amount when the clutch actuator is operated; an input shaft rotation speed detecting portion for detecting an input shaft rotation speed of the input shaft of the automated manual transmission; and a motor rotatably connected to the input shaft or output shaft of the automated manual transmission, wherein, the corresponding relationship correcting portion includes: a speed change operation completion detecting portion for detecting that the speed change operation is completed upon speed change operation of the automated manual transmission; a rotation difference judging portion for judging that an absolute difference between the engine rotation speed and the input shaft rotation speed of the automated manual transmission is equal to or more than a predetermined value under the clutch being engaged; and a clutch torque-operating amount correcting portion for replacing a value of clutch torque corresponding to the clutch actuator operating amount which corresponds to the target clutch torque operated by the clutch actuator by the clutch control portion with the presumed clutch torque calculated by the presumed clutch torque calculating portion.