Wireless communication device, sensor device, and wearable device

A wireless communication device comprising:

• a case having a substantially cylindrical shape and including a first opening at a front surface and a second opening at a back surface, respectively;
• a first cover member that blocks at least a portion of the first opening;
• a support member that supports the first cover member;
• a second cover member that blocks at least a portion of the second opening;
• an insulating member that fills a gap between the support member and the case;
• a display;
• a substrate housed by the case;
• an antenna circuit installed on the substrate;
• and
• a communication circuit installed on the substrate and electrically connected to the antenna circuit, wherein
• the case includes a metal material,
• the first cover member includes a light-transmitting material that allows light from the display to pass through,
• the support member has a substantially cylindrical shape that includes a third opening at a front surface and a fourth opening at a back surface, respectively, and includes a projection portion projecting to an inner side of the third opening and the fourth opening and provided on an inner wall surface connecting to the third opening and the fourth opening,
• the first cover member is supported by the projection portion of the support member, and
• the wireless communication device further comprises an insulating member that fills a gap between the first cover member and each of the projection portion and the inner wall surface of the support member.