A power tool comprising: a housing formed with an inlet hole and an exhaust hole ; a brushless motor supported by the housing ; a power supply circuit comprising at least one circuit element (92B, Q1-Q6) for supplying electric power of a power source to the brushless motor ; a board on which the at least one circuit element (92B, Q1-Q6) is mounted; a board case accommodating therein the board ; and a fan driven by rotation of the brushless motor to generate a cooling air flow flowing from the inlet hole to the exhaust hole in the housing , wherein the housing comprises a first housing , the first housing comprising a grip portion and supporting the brushless motor , wherein the brushless motor comprises a rotation shaft portion extending in a frontward/rearward direction, wherein the housing further comprises a motor case integrally molded in a hollow cylindrical shape extending in the frontward/rearward direction, the motor case supporting the brushless motor , wherein the motor case is formed with a communication hole allowing an interior of the first housing to be communicated with an interior of the motor case , wherein the inlet hole is formed in the first housing , wherein the at least one circuit element (92B, Q1-Q6) is disposed inside the first housing and is cooled by the cooling air flow, characterized in that the first housing further comprises a motor support portion supporting the motor case and having a rear wall portion facing the grip portion in the frontward/rearward direction, wherein a part of the board case is positioned between the motor case and the rear wall portion in the frontward/rearward direction, and that at least part of the inlet hole is positioned between the board case and the communication hole in the frontward/rearward direction. a housing formed with an inlet hole and an exhaust hole ; a brushless motor supported by the housing ; a power supply circuit comprising at least one circuit element (92B, Q1-Q6) for supplying electric power of a power source to the brushless motor ; a board on which the at least one circuit element (92B, Q1-Q6) is mounted; a board case accommodating therein the board ; and a fan driven by rotation of the brushless motor to generate a cooling air flow flowing from the inlet hole to the exhaust hole in the housing , wherein the housing comprises a first housing , the first housing comprising a grip portion and supporting the brushless motor , wherein the brushless motor comprises a rotation shaft portion extending in a frontward/rearward direction, wherein the housing further comprises a motor case integrally molded in a hollow cylindrical shape extending in the frontward/rearward direction, the motor case supporting the brushless motor , wherein the motor case is formed with a communication hole allowing an interior of the first housing to be communicated with an interior of the motor case , wherein the inlet hole is formed in the first housing , wherein the at least one circuit element (92B, Q1-Q6) is disposed inside the first housing and is cooled by the cooling air flow, characterized in that the first housing further comprises a motor support portion supporting the motor case and having a rear wall portion facing the grip portion in the frontward/rearward direction, wherein a part of the board case is positioned between the motor case and the rear wall portion in the frontward/rearward direction, and that at least part of the inlet hole is positioned between the board case and the communication hole in the frontward/rearward direction. <EOS>