This invention provides an electric tool switch enabling fine speed control of an electric tool by an intuitive operation. An electric tool switch 1 includes an operation member 12 turnable in both directions and biased to self-return to a neutral position; a circuit substrate 21 arranged to be orthogonal to a turning shaft of the operation member 12; a slidably moving element 18 which is pressed against the circuit substrate 21 and which is turned with the operation member 12 to slidably contact the circuit substrate 21; and an inversion mechanism 24, 25 for switching a polarity between output terminals according to the turning direction of the operation member from the neutral position; where the circuit substrate 21 is formed with two sets of variable resistor circuits, which close a circuit when the slidably moving element 18 slidably contacts and which resistance value changes according to a contacting position of the slidably moving element 18, electrically connected in parallel on both sides in the turning direction from a position corresponding to the neutral position of the operation member.