An electric working machine includes: a motor； a semiconductor element that is provided in a current path to the motor and completes or interrupts the current path； a circuit board on which the semiconductor element is mounted, a control circuit that turns on and off the semiconductor element to control energization to the motor being assembled to the circuit board； and a heat sink for dissipating heat from the semiconductor element. The semiconductor element is attached to the heat sink via a metal-based board.
