A midsole of a shoe has a low elastic part 20, a high elastic part 22 and an inclined surface 24. The low elastic part 20 and the high elastic part 22 include air bubbles. An ethylene-vinyl acetate copolymer (EVA) is used as a base polymer in the low elastic part 20 and the high elastic part 22. The inclined surface 24 is inclined upward from the inside to the outside. The low elastic part 20 is located to the inside of the inclined surface 24. The high elastic part 22 is located to the outside of the inclined surface 24. An inner high elastic part 26 is located to the inside of a low elastic part 20. The thickness of the low elastic part 20 becomes gradually larger from the outside to the inside along the inclined surface 24. The thickness of the high elastic part 22 becomes gradually larger from the inside to the outside along the inclined surface 24. The width Wa of the inclined surface 24 in left and right direction is 5 mm or more and 100 mm or less.