A touch switch for controlling accessory equipment of a vehicle avoids a malfunction which is caused due to an environmental change such as a change in a state of air, arrival of unnecessary electromagnetic waves, or the like. Conductor plates 20-1 to 20-3 are disposed in an arrangement isolated from one another on a surface opposite to a sensor surface 16T of a touch plate 16 which is touched by a person's hand. The conductor plates 20-1 to 20-3 are each connected to a capacity measurement/control unit 34. The capacity measurement/control unit 34 determines as a judgment value D the absolute value of a value obtained by subtracting a minimum absolute value among changes ΔC1 to ΔC3 in electrostatic capacity from a maximum absolute value among the changes ΔC1 to ΔC3 in electrostatic capacity. The capacity measurement/control unit 34 controls a switch 28 according to the judgment value D.