10. The information processor according to claim 6 , further comprising: a voice guidance information generating unit for outputting voice guidance for prompting a user to give utterance when the cost value fed from the cost calculating unit is not less than a prescribed value.
6. The information processor according to claim 1 , further comprising: a cost calculating unit for calculating, as a cost value indicating user's labor required before executing a function, a difference between a time period in which the interface screen change key unit is continuously operated in the present operation and an average of elapsed time periods until the function execution key unit is operated in the past, which are determined from plural pieces of the past continuous operation information, by using the past continuous operation information which is recorded in the interface screen operation history recording unit and indicates the operation contents according to which the interface screen change key unit is continuously operated until the function execution key unit is operated and by using the current continuous operation information indicating operation contents according to which the interface screen change key unit is operated continuously without any operation of the function execution key unit up to now, wherein the priority recognition word setting unit, when the cost value calculated by the cost calculating unit is not less than the prescribed value, sets release so as to prevent the voice recognition of the word information corresponding to the function whose likelihood value, which is set by the likelihood value providing unit, is less than a prescribed value.