In order to reduce the possibility of erroneous switching of an operation mode, an oscillation circuit, an oscillator, an electronic device and a moving object including: a power source detecting section that detects a power supply state; a determining section that determines an input state of a predetermined signal; and a control section that switches a operation mode when the determining section determines that input of the predetermined signal is detected within a predetermined time after it is detected that power is supplied, and a control method of the oscillator are provided.