A flush toilet cleaned by pressurized flush water, said flush toilet comprising: a toilet main unit provided with a bowl portion, a rim water spouting port and a jet water spouting port both for expelling flush water, and a drain trap pipe, a reservoir tank for storing flush water; flush water supply means for supplying flush water to the rim water spouting port and replenishing the reservoir tank; a pressurizing pump for pressurizing flush water in the reservoir tank; a jet-side water supply path, formed in a convex shape pointing upward, for supplying flush water pressurized by the pressurizing pump to the jet water spouting port, an overflow path, the lower end of which is connected downstream of the highest position of the jet-side water supply, and the upper end of which opens in the upper side of the reservoir tank; and backflow prevention means, provided on the overflow path, for preventing wherein of flush water from the jet-side water supply path to the reservoir tank; wherein a highest position of the jet-side water supply path is set to be equal to or higher than the position of a highest water level in the reservoir tank during a normal operation; an upper end position of the overflow path is set to be equal to or higher than the position of the highest water level in the reservoir tank; the upper end position of the overflow path is set to be higher than the position of a lower end of the overflow path and the position of an accumulated water level in the bowl; and the position of a lower end of the overflow path is set to be equal to or higher than the position of the accumulated water level in the bowl. a toilet main unit provided with a bowl portion, a rim water spouting port and a jet water spouting port both for expelling flush water, and a drain trap pipe, a reservoir tank for storing flush water; flush water supply means for supplying flush water to the rim water spouting port and replenishing the reservoir tank; a pressurizing pump for pressurizing flush water in the reservoir tank; a jet-side water supply path, formed in a convex shape pointing upward, for supplying flush water pressurized by the pressurizing pump to the jet water spouting port, an overflow path, the lower end of which is connected downstream of the highest position of the jet-side water supply, and the upper end of which opens in the upper side of the reservoir tank; and backflow prevention means, provided on the overflow path, for preventing wherein of flush water from the jet-side water supply path to the reservoir tank; wherein a highest position of the jet-side water supply path is set to be equal to or higher than the position of a highest water level in the reservoir tank during a normal operation; an upper end position of the overflow path is set to be equal to or higher than the position of the highest water level in the reservoir tank; the upper end position of the overflow path is set to be higher than the position of a lower end of the overflow path and the position of an accumulated water level in the bowl; and the position of a lower end of the overflow path is set to be equal to or higher than the position of the accumulated water level in the bowl.