A shoe comprising: a flexible shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') having an internal space receiving a foot of a wearer; and a sole body accommodated in the shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') and supporting a sole of the foot of the wearer, wherein the shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') includes a bottom wall portion and a peripheral wall portion erected from a peripheral edge of the bottom wall portion, the bottom wall portion and a portion of the peripheral wall portion adjacent to the bottom wall portion define a lower space of the internal space in which the sole body is disposed, and a portion of the peripheral wall portion located above the portion adjacent to the bottom wall portion defines at least a portion of an upper space of the internal space in which the wearer's foot is inserted, the bottom wall portion covers a lower surface of the sole body and thus has an external surface configuring a tread of the shoe, and the shoe further comprises an upper body accommodated in the shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') and at least covering an instep of the foot of the wearer, wherein the upper body is in a form of a bag having an opening at a portion thereof corresponding to a topline through which the foot of the wearer is inserted, and characterized in that the upper body is disposed in the upper space and the lower space along an inner surface (11a, 12a) of the shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') and the sole body is thus accommodated in the upper body. a flexible shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') having an internal space receiving a foot of a wearer; and a sole body accommodated in the shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') and supporting a sole of the foot of the wearer, wherein the shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') includes a bottom wall portion and a peripheral wall portion erected from a peripheral edge of the bottom wall portion, the bottom wall portion and a portion of the peripheral wall portion adjacent to the bottom wall portion define a lower space of the internal space in which the sole body is disposed, and a portion of the peripheral wall portion located above the portion adjacent to the bottom wall portion defines at least a portion of an upper space of the internal space in which the wearer's foot is inserted, the bottom wall portion covers a lower surface of the sole body and thus has an external surface configuring a tread of the shoe, and the shoe further comprises an upper body accommodated in the shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') and at least covering an instep of the foot of the wearer, wherein the upper body is in a form of a bag having an opening at a portion thereof corresponding to a topline through which the foot of the wearer is inserted, and characterized in that the upper body is disposed in the upper space and the lower space along an inner surface (11a, 12a) of the shell (10A-10R, 10A1-10A2, 10B', 10C', 10H', 10H1, 10H2, 10K') and the sole body is thus accommodated in the upper body.