PROBLEM TO BE SOLVED: To provide a double heat insulation space structure for an agricultural greenhouse, extremely excellent in workability, greatly improving heat insulation effectiveness for energy saving through triply stretching a film across to form double heat insulation space, and enabling cultivation of crops not only in winter but also in summer. SOLUTION: This double heat insulation space structure comprises attaching at prescribed intervals a plurality of film fixtures 3 in a rafter-like form to a roof frame 1 made of iron frames, attaching a transparent film 6C to the film fixture followed by stretching in a planar form to form a roof surface, connecting unit panel fixing brackets 15 onto the film fixtures 3 spread with the film 6C, spreading films 6A and 6B on both the upper and lower surfaces of a quadrilateral frame body 16, and inserting in a planar form a unit panel 13 forming a first heat insulation space part 18A between the films into the fixing brackets one by one, and forming a second heat insulation space part 18B between the bottom of the unit panel 13 and the film 6C. COPYRIGHT: (C)2008,JPO&INPIT
