1. A game apparatus in which a scenario proceeds in such a way that a player character is moved on a field produced in a three-dimensional virtual space in a memory through a controller so as to search and obtain items located on the field, comprising: a language level controller that stores and controls language skill of the player character every kind of language; a sentence item locator that locates two or more sentence items on the field; an item disclosure object locator that locates two or more item disclosure objects on the field; each of the two or more sentence items on which the kind of language and game information are set; each of the two or more item disclosure objects on which a disclosure item, the kind of language and language level are set; a sentence item reader that executes on the sentence item a process of reading the game information that is set on the sentence item by an instruction from a player through the controller; the language level controller that performs whenever the player character reads the sentence item, a process of improving the language skill for the kind of language corresponding to the sentence item; an object reader that executes a process of accessing the item disclosure object by an instruction from the player through the controller; the object reader that compares the language skill of the kind of language corresponding to the item disclosure object of the player character that is controlled through the language level controller and the language level that is set on the item disclosure object with each other, judges whether the language skill is the same as the language level or higher and executes the process of accessing only when the language skill is the same as the language level or higher; and an item development section that executes a process of developing the disclosure item of the item disclosure object on the field when the object reader judged the language skill is the same as the language level or higher.