To hold a nailing machine, wherein a continuous driving mode and a single driving mode are continuously changed between each other, to the single driving mode.

In the nailing machine, a single driving holding mechanism operates a valve system 14 of a starting valve 11 by a contact lever 19 turnably operated by the operation of a trigger lever 16 and a contact arm 17 to drive a hammering mechanism. The end part of the contact arm 17 is provided with a switching operation member 23 setting to switch between the continuous driving mode and the single driving mode, and the trigger lever 16 is provided with a turning regulation member 27 regulating the turning of the contact lever 19. The nailing machine is held to be an ON state when the starting valve system 13 is operated by turning of the contact lever 19 by operating the trigger lever 16 with the turning regulation member 27 in the continuous driving mode.