An operating element device comprising: a pivoting body (11, 62) which is supported by a supporting member (32, 3) so that the pivoting body (11, 62) can pivot about a pivot axis in response to a force directly exerted on the pivoting body (11, 62) by an operator such that the pivoting body (11, 62) functions as a key or operating element; a reaction force generation member which is elastically deformed by a depression exerted in an axis line direction and generates a reaction force against the depression, wherein the reaction force generation member increases the reaction force from a beginning with an increasing amount of elastic deformation by the depression, and buckling to reduce the reaction force after a peak of the reaction force; and a depression portion (11a, 62g) provided on the pivoting body (11, 62), with the reaction force generation member being fastened to be opposed, in the axis line direction, to the depression portion (11a, 62g), so that the depression portion (11a, 62g,) can depress the reaction force generation member in the axis line direction in response to pivoting of the pivoting body (11, 62), wherein the depression portion (11a, 62g) and the reaction force generation member are configured such that the axis line direction of the reaction force generation member exists within an angle between a normal line of a reference face at a point in time when the depression portion (11a, 62g) comes into contact with the reaction force generation member, and a normal line of the reference face at a point in time when the depression portion (11a, 62g) finishes depressing the reaction force generation member, wherein said reference face is a plane including the pivot axis and a depression point of the depression portion (11a, 62g) or said reference face is a depression surface of the depression portion against the reaction force generation member wherein a normal line of the reference face at a point in time when the reaction force of the reaction force generation member reaches the peak becomes parallel to the axis line of the reaction force generation member. a pivoting body (11, 62) which is supported by a supporting member (32, 3) so that the pivoting body (11, 62) can pivot about a pivot axis in response to a force directly exerted on the pivoting body (11, 62) by an operator such that the pivoting body (11, 62) functions as a key or operating element; a reaction force generation member which is elastically deformed by a depression exerted in an axis line direction and generates a reaction force against the depression, wherein the reaction force generation member increases the reaction force from a beginning with an increasing amount of elastic deformation by the depression, and buckling to reduce the reaction force after a peak of the reaction force; and a depression portion (11a, 62g) provided on the pivoting body (11, 62), with the reaction force generation member being fastened to be opposed, in the axis line direction, to the depression portion (11a, 62g), so that the depression portion (11a, 62g,) can depress the reaction force generation member in the axis line direction in response to pivoting of the pivoting body (11, 62), wherein the depression portion (11a, 62g) and the reaction force generation member are configured such that the axis line direction of the reaction force generation member exists within an angle between a normal line of a reference face at a point in time when the depression portion (11a, 62g) comes into contact with the reaction force generation member, and a normal line of the reference face at a point in time when the depression portion (11a, 62g) finishes depressing the reaction force generation member, wherein said reference face is a plane including the pivot axis and a depression point of the depression portion (11a, 62g) or said reference face is a depression surface of the depression portion against the reaction force generation member wherein a normal line of the reference face at a point in time when the reaction force of the reaction force generation member reaches the peak becomes parallel to the axis line of the reaction force generation member.