To provide a heat treatment tool and heat treatment device, in which a surface of a workpiece is uniformly subjected to nitriding treatment and quenching, and thereby the generation of deformation defects on the workpiece can be prevented, in a nitriding-quenching treatment.

On the heat treatment tool 2, a plurality of workpieces W is placed, and the tool is used upon heat treatment of the workpiece W in a heat treatment furnace 1 and upon immersion of the workpiece into cooling oil. The heat treatment tool includes: a tool body 21 on which the workpiece W is placed; and a sidewall 22 surrounding a side periphery of the tool body 21. An upper part and a lower part of the sidewall 22 are fixed to the tool body 21.