A semiconductor device-composing substrate 10 has a support base 12, an interconnect layer 14 including interconnects 13, and an insulating resin layer 16. The semiconductor device-composing substrate 10 also has a mounting region D1 on which a semiconductor chip 30 is to be mounted. The insulating resin layer 16 is formed on the interconnect layer 14. Chip-connecting electrodes 17, external electrode pads 18 and the resin stopper patterns 19 are formed in the insulating resin layer 16. The chip-connecting electrodes 17 are provided in the mounting region D1. The external electrode pads 18 are provided outside the mounting region D1. The resin stopper patterns 19 are provided between the mounting region D1 and the external electrode pads 18.