A wind turbine power generating apparatus includes a wind turbine rotor including at least one blade; a pitch drive part for changing a pitch angle of the at least one blade; a generator configured to be driven by rotational energy of the wind turbine rotor; a circuit breaker for switching a connection state of the generator with respect to a utility grid; and a controller for controlling the wind turbine power generating apparatus. The controller includes a pitch control part configured to control the pitch drive part in a constant rotation-speed control mode for maintaining a rotation speed of the wind turbine rotor at a target rotation speed, before connection of the generator; a connection-condition determination part configured to determine whether a connection determination condition is satisfied; and a connection-command generation part configured to provide the circuit breaker with a connection command to connect the generator to the utility grid.