To provide an engine starting device attaining theft prevention of a vehicle and reducing a manufacturing cost.

The engine starting device is provided with: a transponder 4 that can be carried with a driver and transmits an ID code unique to a vehicle; an antenna 5 transmitting radio wave to the transponder 4 to supply electric power and receiving the ID code transmitted from the transponder 4 started with this electric power; a determining means 6 determining whether the ID code received by the antenna 5 is the preset regular one; an operating knob 7 allowing the start of an engine by operation; and a lock slider 8 for regulating and locking the operation of the operating knob 7. On condition that the received ID code is determined to be regular by the determining means 6, lock by the lock slider 8 is released to allow the start of the engine by the operation of the operating knob 7.