To easily introduce a new type of game machine, prompt the recycle of the game machine, and smoothly perform the rental sales of the game machine in the rental sales of the game machine.

In a sales pattern for renting the game machine, the rented game machine can be replaced during the rental period of the game machine. By this, the new type of game machine can be easily introduced as necessary without requiring much cost at one time. Also an initial introduction period is provided at the initial stage of the rental period, and the number of introduced game machines is gradually increased during the initial introduction period and the total number of the game machines are finally introduced. By this, the introduction of the game machines can be facilitated, and a kick back can be prevented from occurring due to the depreciation of the introduced game machines at the initial stage. In addition, the history of the parts and assembly parts of equipment units forming the game machines is controlled in the rental control of the game machines. By this, the parts of the game machines can be replaced and controlled when the rental game machines are replaced, and thus the recycling of the game machines can be promoted.