Substrate transfer device and method of cooling arm

A substrate transfer device that transfers a substrate, comprising:

• a transfer arm including a substrate support that supports the substrate, and an arm that is connected to the substrate support and moves the substrate support;
• a cooler configured to distribute and supply a cooling fluid from a fluid supply source to each of a plurality of cooling target regions of the arm;
• a measuring part configured to measure a temperature of each of the cooling target regions;
• and
• a controller configured to:
• calculate a thermal index for each of the cooling target regions based on an amount of change of the temperature of each of the cooling target regions measured by the measuring part from a reference temperature and a degree of influence of the temperature of each of the cooling target regions;
• determine a distribution ratio of the cooling fluid from the fluid supply source by the cooler based on the thermal index;
• and
• control the cooler to distribute the cooling fluid from the fluid supply source at the distribution ratio determined based on the thermal index,
• wherein the degree of influence is a predetermined value for each of the cooling target regions, the predetermined value being proportional to a distance from the substrate support to each of the cooling target regions.