An apparatus for controlling operation of a walk-behind electric lawn mower equipped with a frame configured to be movable over a lawn growth area by a user by hand from behind; an electric motor having three-phase coils and mounted on the frame; a blade cutter provided at an underneath surface of the frame to be connected to the electric motor and configured to cut grass on the lawn growth area when driven by the electric motor; a rechargeable battery mounted on the frame to be connected to the electric motor and configured to discharge electric power so as to apply to the electric motor as operating electric power and to be charged by a regenerative electric current that is generated by the electric motor during regenerative braking of rotation of the blade cutter; and a motor driver circuit configured to adjust supply of the operating electric power to the three-phase coils of the electric motor: wherein the apparatus includes: a control unit configured to control operation of the motor driver circuit having: a stop instruction input determination unit (36a1) configured to determine whether an instruction to stop the electric motor is inputted by the user; a regenerative braking implementation unit (36a2) configured to control the operation of the motor driver circuit to implement regenerative braking that outputs regenerative electric current from the three-phase coils of the electric motor, when it is determined by the stop instruction input determination unit that the instruction to stop the electric motor is inputted; and a motor rotational speed determination unit (36a3) configured to determine whether a rotational speed of the electric motor; characterized in that: the motor rotational speed determination unit (36a3) is configured to determine whether a rotational speed of the electric motor is equal to or less than a switching rotational speed, when the regenerative braking is implemented by the regenerative braking implementation unit; and in that the control unit further has a short-circuit braking switching unit (36a4) configured to control the operation of the motor driver circuit to switch from the regenerative braking to short-circuit braking that short-circuits the three-phase coils of the electric motor, when it is determined by the rotational speed determination unit that the rotational speed of the electric motor is equal to or less than the switching rotational speed. a stop instruction input determination unit (36a1) configured to determine whether an instruction to stop the electric motor is inputted by the user; a regenerative braking implementation unit (36a2) configured to control the operation of the motor driver circuit to implement regenerative braking that outputs regenerative electric current from the three-phase coils of the electric motor, when it is determined by the stop instruction input determination unit that the instruction to stop the electric motor is inputted; and a motor rotational speed determination unit (36a3) configured to determine whether a rotational speed of the electric motor; characterized in that: the motor rotational speed determination unit (36a3) is configured to determine whether a rotational speed of the electric motor is equal to or less than a switching rotational speed, when the regenerative braking is implemented by the regenerative braking implementation unit; and in that the control unit further has a short-circuit braking switching unit (36a4) configured to control the operation of the motor driver circuit to switch from the regenerative braking to short-circuit braking that short-circuits the three-phase coils of the electric motor, when it is determined by the rotational speed determination unit that the rotational speed of the electric motor is equal to or less than the switching rotational speed. the motor rotational speed determination unit (36a3) is configured to determine whether a rotational speed of the electric motor is equal to or less than a switching rotational speed, when the regenerative braking is implemented by the regenerative braking implementation unit; and in that the control unit further has a short-circuit braking switching unit (36a4) configured to control the operation of the motor driver circuit to switch from the regenerative braking to short-circuit braking that short-circuits the three-phase coils of the electric motor, when it is determined by the rotational speed determination unit that the rotational speed of the electric motor is equal to or less than the switching rotational speed.