Magnetic sensor assembly 1 has first member 10 having first to third magnetic sensors 13A to 13C, and second member 20 having first to third magnets 22A to 22C. Second member 20 can be moved in X and Y directions and can be rotated about a Z axis relative to first member 10. Output of first to third magnetic sensors 13A to 13C monotonously changes. A change of the output of first magnetic sensor and a change of the output of second magnetic sensor are different from each other. First to third magnets are positioned on first to third straight lines L1 to L3. A first angle that is formed between first straight line L1 and X axis, a second angle that is formed between second straight line L2 and X axis, and a third angle that is formed between third straight line L3 and Y axis are same.