A flush toilet apparatus that can reduce the total amount of wash water supplied to a bowl portion, even though a jet-pump water supply mechanism is mounted on a toilet body. A jet pump unit induces a jet pump action for making a flow rate of water flowing inside of a throat pipe higher than a flow rate of water injected from a nozzle to supply water at the increased flow rate to water ejection portions, and the flush toilet apparatus switches a channel state of the jet pump unit to sequentially execute a first step, in which water at a first flow rate is supplied to the water ejection portions, and a second step, in which water at a second flow rate lower than the first flow rate is supplied to the water ejection portions.