Straight Tube Lamp and Luminaire

A luminaire comprising:

• a straight tube lamp including:
• a straight tube having translucency;
• a luminous body including a board and a semiconductor light-emitting element disposed on one surface side of the board along a longitudinal direction;
• a metal base including an attachment part which is disposed on other surface side of the board to cause the one surface side of the board to face an inner surface of the tube, a base part which is formed along a longitudinal direction on the inner surface of the tube most distant from the attachment part in an opposite side to the one surface side of the board, a pair of side parts which are provided at both sides of the attachment part in a short direction and protrude from the attachment part toward the one surface side of the board, and a coupling part which couples the base part and one of the attachment part and the pair of side parts, in which the base part and the pair of side parts are thicker than the attachment part and the coupling part;
• and a cap which includes a power-supply contact connected to the semiconductor light-emitting element and is disposed at an end of the tube;
• an equipment main body including a socket to which the cap of the straight tube lamp is connected;
• and
• a lighting circuit to light the straight tube lamp.