Mill, milling machine, and beverage preparation apparatus

A mill comprising:

• a first mill which has a first grinding region;
• a second mill which has a second grinding region opposed to the first grinding region and is provided to be rotatable relatively to the first mill;
• and
• a heat radiation mechanism which is provided in at least one of the first mill and the second mill and radiates friction heat generated as a result of rotation of the first mill and the second mill relative to each other, wherein
• the heat radiation mechanism is provided in a portion except for the first grinding region and the second grinding region,
• the first mill has a main surface that includes the first grinding region, a surface located opposite to the main surface that includes the first grinding region, and a first circumferential surface connecting the main surface of the first mill and the surface of the first mill,
• the second mill has a main surface that includes the second grinding region, a surface located opposite to the main surface that includes the second grinding region, and a second circumferential surface connecting the main surface of the second mill and the surface of the second mill, and
• the heat radiation mechanism is provided in at least one of the first circumferential surface and the second circumferential surface.