The purpose of the present invention is to provide a ball glove structure that improves glove functionality for a player of baseball or softball even through provided with a box-like protective thumb-slot. The ball glove generally comprises an outer shell where the shell part Is formed by sewing together a ball catching palm surface part (1) and a backing surface part (2) provided with thumb and finger stalls or slots with a lace (3). The inventive glove structure comprises (A) a box-like thumb protective stall or slot (21) provided with a hem spread opening (21e) having an enlarged angle (α) at the bottom portion with regard to the center line of the thumb slot for easy movement of the thumb bottom at the time of opening/closing of the glove and also (B) a fixing structure comprising a pair of slits (10a, 10a) for dividing a hand opening band (5) into two parts; one is a thumb side and the other is a little finger side and a pair of straps (11a,11b) for fixing the bottom of the index finger to make a secure movement axis for opening/closing the glove as well as fastening the divided hand opening band for preventing the glove hand from slipping out from the hand opening band. Preferably, the little finger is fixed by the adjustable strap structure (23) to fix the little finger.