a handheld electromotive tool capable of efficient execution of a floor board and a ceiling board is provided . the tool is used in combination with a beam emitting device for emitting a radiation beam in a reference plane , and is provided with a housing held by an operator . the housing has a work member driven by an electric motor and a photo detector for receiving the radiation beam projected in the reference plane . output signals indicating positional deviation of the photo detector from the reference plane are generated on the basis of output of the photo detector . rotation of the motor is controlled as follows . rotation of the electric motor is stopped when the radiation beam is received at a reference position of the photo detector . the electric motor rotates at high speed until the radiation beam is received in the vicinity of the reference position . the electric motor rotates at low speed from the time the radiation beam is received in the vicinity of the reference position to the time the radiation beam is received at the reference position .