A system comprising at least one battery changing station (ST1..ST3) and a route searching apparatus configured to search for a route through which a moving body which moves by electric energy from a changeable battery reaches a destination, the route searching apparatus comprising: position obtaining means configured to obtain a current position of the moving body; predicting means configured to predict a time of arrival at a battery changing station (ST1..ST3) based on a position of the battery changing station (ST1..ST3), adding the time of arrival to a request for stock information of a changeable battery in the battery changing station (ST1..ST3) and transmitting the request to the battery changing station (ST1..ST3); stock information obtaining means configured to obtain the stock information comprising a charge amount of a changeable battery, providable by the battery changing station, from the battery changing station (ST1..ST3); estimating means configured to estimate a movable range based on a residual amount of a changeable battery mounted in the moving body; and searching means configured to search for a route through which the moving body reaches the destination or, if the destination is not reachable, another battery changing station via the battery changing station (ST1..ST3), characterized in that the route searching apparatus further comprises a destination and residual amount designating means configured to designate, by a user, the destination and a residual amount of the changeable battery, which should at least remain when the moving body arrives at the destination; and the battery changing station (ST1..ST3) comprises a predicting means configured to predict a charge amount of the changeable battery at the time of arrival taking into account a change of charge amount due to charging of the changeable battery between the time of receiving the request and the time of arrival and adding the predicted charge amount to the stock information transmitted to the route searching apparatus, wherein the searching means is configured to search for said route based on the designated residual amount, the stock information and the movable range by determining whether the moving body can reach the destination or, if the destination is not reachable, another battery changing station in a case where the battery is changed with a changeable battery having the predicted charge amount in the battery changing station (ST1..ST3). position obtaining means configured to obtain a current position of the moving body; predicting means configured to predict a time of arrival at a battery changing station (ST1..ST3) based on a position of the battery changing station (ST1..ST3), adding the time of arrival to a request for stock information of a changeable battery in the battery changing station (ST1..ST3) and transmitting the request to the battery changing station (ST1..ST3); stock information obtaining means configured to obtain the stock information comprising a charge amount of a changeable battery, providable by the battery changing station, from the battery changing station (ST1..ST3); estimating means configured to estimate a movable range based on a residual amount of a changeable battery mounted in the moving body; and searching means configured to search for a route through which the moving body reaches the destination or, if the destination is not reachable, another battery changing station via the battery changing station (ST1..ST3), characterized in that the route searching apparatus further comprises a destination and residual amount designating means configured to designate, by a user, the destination and a residual amount of the changeable battery, which should at least remain when the moving body arrives at the destination; and the battery changing station (ST1..ST3) comprises a predicting means configured to predict a charge amount of the changeable battery at the time of arrival taking into account a change of charge amount due to charging of the changeable battery between the time of receiving the request and the time of arrival and adding the predicted charge amount to the stock information transmitted to the route searching apparatus, wherein the searching means is configured to search for said route based on the designated residual amount, the stock information and the movable range by determining whether the moving body can reach the destination or, if the destination is not reachable, another battery changing station in a case where the battery is changed with a changeable battery having the predicted charge amount in the battery changing station (ST1..ST3).