The sanitary washing apparatus according to the invention comprises a cylinder, and a piston slider including a squirting port in a front end part and a second inflow port in a rear end part and internally including a flow channel connecting the squirting port with the second inflow port, The cylinder includes biasing means configured to reciprocably house the piston slider and to bias the piston slider backward, The rear end part of the piston slider includes a water pressure receiving part configured to receive water pressure of water flowing into the cylinder, and Pressure of water flowing from the first inflow port into the cylinder is received by the water pressure receiving part of the piston slider so that the piston slider is advanced to a use position against biasing force of the biasing means.An object of the invention is to provide a sanitary washing apparatus capable of suppressing jetting of water from the squirting port during the advance of the hydraulic nozzle based on a simple configuration, and also capable of maintaining a clean state after use of the nozzle without leaving water in its flow channel.