A drip-proof structure of an electronic component, comprising: a rotary body that comprises a main body comprising a circular outer circumferential surface as an operating portion and a shaft portion provided on one side surface of the main body; a first case that comprises a bearing rotatably supporting the shaft portion of the rotary body ; a second case that is provided integral with the first case so as to have an opening therebetween, supports the other side surface of the main body of the rotary body , and houses, together with the first case , the rotary body while exposing a portion of the circular outer circumferential surface of the rotary body through the opening; a sliding piece that is provided on the rotary body located inside the first and second cases and changes its position to follow rotation of the rotary body ; a circuit board that comprises a sliding contact pattern to be in sliding contact with the sliding piece and outputs an output signal corresponding to the rotational position of the rotary body ; a cover that comprises an exposure opening for exposing the portion of the circular outer circumferential surface of the rotary body exposed through the opening and covers the first and second cases and the circuit board ; first and second drip-proof members arranged between the first case and the cover and between the second case and the cover , respectively, characterized in that it further comprises a drip-proof processing portion (B1) provided between the shaft portion of the rotary body and the bearing , wherein the drip-proof processing portion (B1) comprises an end portion of a cylindrical protruding portion serving as the bearing and receiving the shaft portion of the rotary body inserted therein, and a drip-proof recess formed on the shaft portion of the rotary body so as to be concentrically with the shaft portion and receiving the end portion of the protruding portion inserted therein. a rotary body that comprises a main body comprising a circular outer circumferential surface as an operating portion and a shaft portion provided on one side surface of the main body; a first case that comprises a bearing rotatably supporting the shaft portion of the rotary body ; a second case that is provided integral with the first case so as to have an opening therebetween, supports the other side surface of the main body of the rotary body , and houses, together with the first case , the rotary body while exposing a portion of the circular outer circumferential surface of the rotary body through the opening; a sliding piece that is provided on the rotary body located inside the first and second cases and changes its position to follow rotation of the rotary body ; a circuit board that comprises a sliding contact pattern to be in sliding contact with the sliding piece and outputs an output signal corresponding to the rotational position of the rotary body ; a cover that comprises an exposure opening for exposing the portion of the circular outer circumferential surface of the rotary body exposed through the opening and covers the first and second cases and the circuit board ; first and second drip-proof members arranged between the first case and the cover and between the second case and the cover , respectively, characterized in that it further comprises a drip-proof processing portion (B1) provided between the shaft portion of the rotary body and the bearing , wherein the drip-proof processing portion (B1) comprises an end portion of a cylindrical protruding portion serving as the bearing and receiving the shaft portion of the rotary body inserted therein, and a drip-proof recess formed on the shaft portion of the rotary body so as to be concentrically with the shaft portion and receiving the end portion of the protruding portion inserted therein. <EOS>