Abstract: Provided are a long-lived target for a neutron-generating device and a method for manufacturing the target therefore. The target is for a neutron-generating device and includes: a metal substrate retaining a target material; and a metal thin film for sealing that holds the target material at a retention surface X side. The retention surface X side of the metal substrate includes: a frame portion; and an embossed structure including: a plurality of island portions that are surrounded by the frame portion; and the rest recessed portion that is created by decreasing a thickness of a region other than the frame portion and the island portions by a thickness of the target material. The metal thin film and surfaces of the frame portion and the island portions are subjected to hot isostearic pressing (HIP) bonding to seal the target material onto the recessed portion by using the metal thin film.