In a control device for a continuously variable transmission comprising a controller for controlling the speed ratio of a belt continuously variable transmission via an actuator, the continuously variable transmission is capable of selecting a first speed ratio i1 corresponding to a biggest speed ratio and a second speed ratio i2 that is smaller than the first speed ratio as a startup speed ratio. The controller switch the second speed ratio to the first speed ratio when the rotation speed of a primary side pulley falls to a predetermined rotation speed Nt during vehicle deceleration, even if the second speed ratio has been selected, and switches the first speed ratio to the second speed ratio when the rotation speed of the primary side pulley rises to the predetermined rotation speed during vehicle startup.