A flush toilet for discharging waste wherein the flush toilet is flushed with flush water supplied from a flush water source, having: a bowl portion comprising a waste receiving surface having a bowl shape, and a rim portion formed above and outside an entire perimeter of the bowl portion to form a top edge of the toilet; a discharge path for discharging waste, an inlet of which is connected underneath the bowl portion; a forward-opening spout portion in a front area on the left of the flush toilet for spouting flush water from a front region of the bowl portion toward a front end of the bowl portion and forming a swirling flow from the front end toward a rear of the bowl portion; and a water conduit extending inside and formed by the rim portion and communicating with the forward-opening spout portion, through which supplied flush water is spouted; wherein the rim portion comprises: a rim top inside corner portion forming an edge on the inside of a top portion of the rim portion between a rim top surface portion and an inside perimeter wall surface; and a rim top outside corner portion forming an edge on the outside of the top portion of the rim portion between the rim top surface portion and an outside perimeter wall surface; in at least part of the entire perimeter of the rim portion, a rounding of the rim top inside corner portion is formed to be larger than a rounding of the rim top outside corner portion, and the minimum curvature radius of a curved surface of the rim top inside corner portion is formed to be larger than the minimum curvature radius of a curved surface of the rim top outside corner portion, wherein on the front side of the bowl portion ahead of the spout portion, the inside perimeter wall surface, formed along the entire perimeter on the inside of the rim portion, and the rim top inside corner portion are formed in a shape which overhangs toward the inside of the bowl portion, whereby the inside perimeter wall surface is formed to slope toward the inside as it rises from bottom to top, wherein the rim top inside corner portion forms a curved portion smoothly linking the rim top surface portion which is horizontally-oriented and the inside perimeter wall surface. a bowl portion comprising a waste receiving surface having a bowl shape, and a rim portion formed above and outside an entire perimeter of the bowl portion to form a top edge of the toilet; a discharge path for discharging waste, an inlet of which is connected underneath the bowl portion; a forward-opening spout portion in a front area on the left of the flush toilet for spouting flush water from a front region of the bowl portion toward a front end of the bowl portion and forming a swirling flow from the front end toward a rear of the bowl portion; and a water conduit extending inside and formed by the rim portion and communicating with the forward-opening spout portion, through which supplied flush water is spouted; wherein the rim portion comprises: a rim top inside corner portion forming an edge on the inside of a top portion of the rim portion between a rim top surface portion and an inside perimeter wall surface; and a rim top outside corner portion forming an edge on the outside of the top portion of the rim portion between the rim top surface portion and an outside perimeter wall surface; in at least part of the entire perimeter of the rim portion, a rounding of the rim top inside corner portion is formed to be larger than a rounding of the rim top outside corner portion, and the minimum curvature radius of a curved surface of the rim top inside corner portion is formed to be larger than the minimum curvature radius of a curved surface of the rim top outside corner portion, wherein on the front side of the bowl portion ahead of the spout portion, the inside perimeter wall surface, formed along the entire perimeter on the inside of the rim portion, and the rim top inside corner portion are formed in a shape which overhangs toward the inside of the bowl portion, whereby the inside perimeter wall surface is formed to slope toward the inside as it rises from bottom to top, wherein the rim top inside corner portion forms a curved portion smoothly linking the rim top surface portion which is horizontally-oriented and the inside perimeter wall surface. a rim top inside corner portion forming an edge on the inside of a top portion of the rim portion between a rim top surface portion and an inside perimeter wall surface; and a rim top outside corner portion forming an edge on the outside of the top portion of the rim portion between the rim top surface portion and an outside perimeter wall surface; in at least part of the entire perimeter of the rim portion, a rounding of the rim top inside corner portion is formed to be larger than a rounding of the rim top outside corner portion, and the minimum curvature radius of a curved surface of the rim top inside corner portion is formed to be larger than the minimum curvature radius of a curved surface of the rim top outside corner portion, wherein on the front side of the bowl portion ahead of the spout portion, the inside perimeter wall surface, formed along the entire perimeter on the inside of the rim portion, and the rim top inside corner portion are formed in a shape which overhangs toward the inside of the bowl portion, whereby the inside perimeter wall surface is formed to slope toward the inside as it rises from bottom to top, wherein the rim top inside corner portion forms a curved portion smoothly linking the rim top surface portion which is horizontally-oriented and the inside perimeter wall surface.