An injection foam molding apparatus for manufacturing a one-piece shoe or sole having various colors, hardnesses and specific gravities, using ethylene-vinyl acetate ethylene-poly olefin compounds and thermoplastic resins, comprising: a top mold including a molding space having a shape corresponding to an upper part of a shoe or sole; a bottom mold including a molding space having a shape corresponding to a lower part of a shoe or sole; a middle mold located between the top mold and the bottom mold to separate the two molding spaces (101, 201) from each other; a resin supply unit supplying different thermoplastic resins into the molding space defined between the top mold and the middle mold and the molding space defined between the middle mold and the bottom mold, respectively; a transfer unit moving the middle mold into a space between the top mold and the bottom mold; and a pressing unit pressing the thermoplastic resins charged in the molding spaces (101, 201) by moving the top mold and bottom mold upward and downward, wherein the thermoplastic resins are injected into the top mold and bottom mold in a state in which the top mold and bottom mold are coupled with the middle mold, and then form the upper part and lower part of a shoe or sole in a state in which the top mold and the bottom mold are pressed against the middle mold, the middle mold is separated therefrom, and then the top mold and bottom mold, including the upper part and lower part of the shoe or sole, respectively, are pressed to each other, thereby forming the upper part and lower part of the shoe or sole into one body, wherein the top mold comprises a moving core forming an inner shape of the shoe, characterized in that the moving core is provided in the top mold such that it can move upward and downward; wherein the moving core is provided thereon with a rod-shaped moving member inserted into a through-hole formed in an upper portion of the top mold such that the moving core can move vertically along the through-hole and the moving member is provided therearound with a spring, such that the moving member pushes the moving core downward; wherein a holding hole is formed from one side of the top mold to the moving member, and a bolt is inserted into the holding hole such that the bolt presses the moving member to hold the moving core, or enables the moving core to move freely, when the bolt moves forward or backward; and wherein a plurality of protrusions are formed on one side of the middle mold, the transfer unit being configured for lifting up the protrusions while being in contact with the lower surfaces of the protrusions and then moving forward and backward. a top mold including a molding space having a shape corresponding to an upper part of a shoe or sole; a bottom mold including a molding space having a shape corresponding to a lower part of a shoe or sole; a middle mold located between the top mold and the bottom mold to separate the two molding spaces (101, 201) from each other; a resin supply unit supplying different thermoplastic resins into the molding space defined between the top mold and the middle mold and the molding space defined between the middle mold and the bottom mold, respectively; a transfer unit moving the middle mold into a space between the top mold and the bottom mold; and a pressing unit pressing the thermoplastic resins charged in the molding spaces (101, 201) by moving the top mold and bottom mold upward and downward, wherein the thermoplastic resins are injected into the top mold and bottom mold in a state in which the top mold and bottom mold are coupled with the middle mold, and then form the upper part and lower part of a shoe or sole in a state in which the top mold and the bottom mold are pressed against the middle mold, the middle mold is separated therefrom, and then the top mold and bottom mold, including the upper part and lower part of the shoe or sole, respectively, are pressed to each other, thereby forming the upper part and lower part of the shoe or sole into one body, wherein the top mold comprises a moving core forming an inner shape of the shoe, characterized in that the moving core is provided in the top mold such that it can move upward and downward; wherein the moving core is provided thereon with a rod-shaped moving member inserted into a through-hole formed in an upper portion of the top mold such that the moving core can move vertically along the through-hole and the moving member is provided therearound with a spring, such that the moving member pushes the moving core downward; wherein a holding hole is formed from one side of the top mold to the moving member, and a bolt is inserted into the holding hole such that the bolt presses the moving member to hold the moving core, or enables the moving core to move freely, when the bolt moves forward or backward; and wherein a plurality of protrusions are formed on one side of the middle mold, the transfer unit being configured for lifting up the protrusions while being in contact with the lower surfaces of the protrusions and then moving forward and backward.