A tap changer and a method for measuring a contact sequence of a tap changer is provided. The tap changer includes a cylinder and a shaft that is rotatably arranged inside the cylinder, the cylinder is provided with fixed contacts, the shaft is provided with a contact circuit facing the cylinder and including mechanical contacts, which mechanical contacts are adapted to selectively mate with the fixed contacts of the cylinder upon rotation of the shaft, the contact circuit also includes at least two measuring points for measuring the function of the contact circuit. The tap changer includes at least one measuring contact device, which is electrically connected to the respective measuring points in the contact circuit, and which the measuring contact device is arranged inside the shaft. This facilitates access to the measuring points of the tap changer.