A hammer drill includes a housing, a tool holder, a hammering member, a gear, and a conversion member. The gear is switched to a first state where a rotation of the intermediate shaft is transmitted and a second state where the rotation of the intermediate shaft is not transmitted, and a mode switching member is configured to perform a switching operation of the state of the gear from an outside of the housing. The switching of the state of the gear by the mode switching member provides at least two operation modes of a hammer drill mode where the gear integrally rotates with the intermediate shaft to generate the rotation and a reciprocation of the hammering member on the tool holder and a hammer mode where the gear is separated from the rotation of the intermediate shaft to generate only the reciprocation of the hammering member to be selectable.