Use of a panel-like formed product (1, 10) made of a metal plate as a door inner panel of a vehicle, the panel-like formed product (1, 10) comprising: a polygonal top board, two or more vertical walls extending from two or more sides of the top board among all sides of the top board defining an outer edge of the top board, the vertical walls including at least two adjacent vertical walls extending from at least two adjacent sides of the top board; and a flange connecting to lower ends of the vertical walls and spreading in directions in which the top board spreads; wherein: the top board includes: a frame portion including the two or more sides of the top board from which the vertical walls extend; and a concave portion which is located at an inner side of the frame portion and recedes from the frame portion; the at least two adjacent vertical walls include: a first vertical wall section; a stair connecting to a lower end of the first vertical wall section and spreading in the directions in which the top board spreads; and a second vertical wall section connecting to an outer edge of the stair and extending in a direction in which the first vertical wall section extends; the flange connects to a lower end of the second vertical wall section; and wherein none of the vertical walls and the frame portion extends from a side positioned at an upper side in the vehicle, among all sides of the top board defining the outer edge of the top board. a polygonal top board, two or more vertical walls extending from two or more sides of the top board among all sides of the top board defining an outer edge of the top board, the vertical walls including at least two adjacent vertical walls extending from at least two adjacent sides of the top board; and a flange connecting to lower ends of the vertical walls and spreading in directions in which the top board spreads; wherein: the top board includes: a frame portion including the two or more sides of the top board from which the vertical walls extend; and a concave portion which is located at an inner side of the frame portion and recedes from the frame portion; the at least two adjacent vertical walls include: a first vertical wall section; a stair connecting to a lower end of the first vertical wall section and spreading in the directions in which the top board spreads; and a second vertical wall section connecting to an outer edge of the stair and extending in a direction in which the first vertical wall section extends; the flange connects to a lower end of the second vertical wall section; and wherein none of the vertical walls and the frame portion extends from a side positioned at an upper side in the vehicle, among all sides of the top board defining the outer edge of the top board. the top board includes: a frame portion including the two or more sides of the top board from which the vertical walls extend; and a concave portion which is located at an inner side of the frame portion and recedes from the frame portion; a frame portion including the two or more sides of the top board from which the vertical walls extend; and a concave portion which is located at an inner side of the frame portion and recedes from the frame portion; the at least two adjacent vertical walls include: a first vertical wall section; a stair connecting to a lower end of the first vertical wall section and spreading in the directions in which the top board spreads; and a second vertical wall section connecting to an outer edge of the stair and extending in a direction in which the first vertical wall section extends; a first vertical wall section; a stair connecting to a lower end of the first vertical wall section and spreading in the directions in which the top board spreads; and a second vertical wall section connecting to an outer edge of the stair and extending in a direction in which the first vertical wall section extends; the flange connects to a lower end of the second vertical wall section; and wherein none of the vertical walls and the frame portion extends from a side positioned at an upper side in the vehicle, among all sides of the top board defining the outer edge of the top board.