A variable resistor includes: a main body and a rotating part vertically separated away from each other, among which the main body includes: a substrate having a first main surface, a second main surface and a through hole vertically penetrating the first main surface and the second main surface; a first conductive portion and a second conductive portion provided on the first main surface; a resistor body connected thereto; an electrode positioned closer to the through hole than the resistor body; and a third conductive portion (i) provided on each of the second main surface and a partition wall surface for partitioning the through hole and (ii) connected to the electrode, and the rotating part includes: an opposing part rotatable in a circumferential direction; and a slider configured to conductively slide as the rotating part rotates.