To provide an openable holding tool to facilitate mounting of an object to be held, which is hardly separated, and suitable for use as a goggle holder for a helmet having a holding force not lowered even when it is used for a long period.

An openable holding tool 7 is constituted such that A plate-form base plate part 11 having given length and width and an opening closing part 12 are openable around a coupling part 13 serving as an axis and integrally intercoupled on one end side in a longitudinal direction thereof, and engaging parts 15 and 16, formed approximately in an L-shape as seen from a side, provided at a tip part with engaging claws 15a and 16a are arranged in an engaging and disengaging state in the vicinity of the other ends in a longitudinal direction of the base plate part 11 and the opening closing part 12, and by integrally erecting the engaging parts 15 and 16 from the opposite surfaces of the base plate part 11 and the opening closing part 12 such that the engaging parts 15 and 16 are engaged with and disengaged from each other, a holding space 14 formed between the base plate part 11 and the opening closing part 12 is closed and released through engagement and disengagement between the engaging parts 15 and 16. The engaging part 16 on the opening closing part 12 side is arranged further externally of the holding space 14 than the engaging part 15 on the base plate part 11 side and at least the intermediate part in a longitudinal direction of the opening closing part 12 is elastically deformable.