Seat hammock for a child

The seat hammock (30) comprises a seat surface portion (31), a backrest surface portion (32) and a pair of lower side surface portions (33) extending to rise upward from both side edges of the seat surface portion (31) in a used state. Each lower side surface portion (33) has a bottom connection end (33a) connected to a side edge of the seat surface portion (31), a back connection end (33b), and an upper connection end (33c). The back connection end (33b) is provided behind a back surface of the backrest surface portion (32) so as to overlap with it and connected to the back surface of the backrest surface portion at a position inside of the backrest surface portion at a distance from both side edges. The upper connection end (33c) is connected to an upward extension frame member (41) extending upward from a rear end of a member forming a seat portion of the child-care instrument.