An electric tool, comprising a sanding mechanism configured to sand a target object, a motor configured to drive the sanding mechanism, a battery pack configured to supply the motor with electric power, and a housing to which the sanding mechanism, the motor and the battery pack are fixed, wherein the motor includes a rotary shaft configured to transmit rotary drive power to the sanding mechanism, the housing includes a handle that allows a user to hold, the sanding mechanism, the motor, the battery pack and the handle are arranged in one direction, and the battery pack has a columnar shape or rectangular columnar shape and is the same as or narrower than the housing in thickness, the rotary shaft of the motor is elongated in the one direction, the housing has a back end face in a lengthwise direction of the housing, the back end face being provided with an engagement recess in which one end part of the battery pack is to be detachably fitted, the battery pack includes the one end part and a remaining part other than the one end part, the lengthwise direction of the housing is a fore-aft direction of the housing, in a state where the one end part of the battery pack is fitted in the engagement recess, the remaining part of the battery pack protrudes straight backward from the housing, in a state where the one end part of the battery pack is inserted into the engagement recess, engagement projections are engaged with engagement hollows, characterised in that one of the engagement hollows and the engagement projections are provided in an inner peripheral face of the engagement recess, the other of the engagement hollows and the engagement projections are provided in a front part of an outer peripheral face of the battery pack, the back end face of the housing is inclined relative to the lengthwise direction of the housing. a sanding mechanism configured to sand a target object, a motor configured to drive the sanding mechanism, a battery pack configured to supply the motor with electric power, and a housing to which the sanding mechanism, the motor and the battery pack are fixed, wherein the motor includes a rotary shaft configured to transmit rotary drive power to the sanding mechanism, the housing includes a handle that allows a user to hold, the sanding mechanism, the motor, the battery pack and the handle are arranged in one direction, and the battery pack has a columnar shape or rectangular columnar shape and is the same as or narrower than the housing in thickness, the rotary shaft of the motor is elongated in the one direction, the housing has a back end face in a lengthwise direction of the housing, the back end face being provided with an engagement recess in which one end part of the battery pack is to be detachably fitted, the battery pack includes the one end part and a remaining part other than the one end part, the lengthwise direction of the housing is a fore-aft direction of the housing, in a state where the one end part of the battery pack is fitted in the engagement recess, the remaining part of the battery pack protrudes straight backward from the housing, in a state where the one end part of the battery pack is inserted into the engagement recess, engagement projections are engaged with engagement hollows, characterised in that one of the engagement hollows and the engagement projections are provided in an inner peripheral face of the engagement recess, the other of the engagement hollows and the engagement projections are provided in a front part of an outer peripheral face of the battery pack, the back end face of the housing is inclined relative to the lengthwise direction of the housing.