Impact tool

A power tool comprising:

• a motor capable of normally rotating and reversely rotating;
• a hammer rotated in a normal rotation direction or a reverse rotation direction by a driving force being supplied thereto from the motor;
• an anvil struck and rotated by the rotation of the hammer,
• a tip tool holding portion capable of holding a tip tool and transmitting the rotation of the anvil to the tip tool;
• an electric power supply unit which alternately switches between normal rotation electric power or reverse rotation electric power so as to be supplied to the motor;
• and
• a control unit which controls the electric power supply unit so as to increase the ratio of a period during which the reverse rotation electric power is supplied with respect to a period during which the normal rotation electric power is supplied, with an increase in an electric current which flows into the motor.