To provide a mechanical detection element and a detector high in sensitivity.

The mechanical detection element, wherein the minute force impressed on a cantilever 1A is detected by the change of resistance caused by the piezoelectric resistance effect, is constituted of: the micro-fabricated cantilever 1A; electrodes 2, 3 capable of measuring the resistance value of a resistance body composed of the cantilever 1A, and a carbon nanotube 4 for measuring the objective resistance through the electrodes 2, and 3.