The present invention discloses a thumb fixing device including a body and at least one strap element. The body includes a base portion, a thumb fixing portion, a web space supporting portion and at least one through hole. The base portion includes a palm supporting portion and a thenar supporting portion. The palm supporting portion has an arcuate recessed portion corresponding to the palm, and the thenar supporting portion has an opening corresponding to the thenar portion of the palm. The thumb fixing portion is integrally connected to the side of the base portion near the thenar supporting portion. The web space supporting portion is integrally connected between the thumb fixing portion and the base portion, and the thenar supporting portion includes a support block. The strap element is disposed on the body for fixing the body to the palm. Therefore, the thumb can be effectively supported and fixed, and the discomfort feelings of humid and airtight of the palm can be prevented.本創作提供一種拇指固定器,包含一本體以及至少一固定帶。本體包含一基部、一拇指固定部、一虎口支撐部以及至少一穿孔。基部包含一手掌支撐部以及一魚際支撐部,手掌支撐部具有一弧形凹陷部,弧形凹陷部對應抵靠於手掌,魚際支撐部對應於手掌之魚際部具有一開口。拇指固定部一體連接於基部靠近魚際支撐部的一側。虎口支撐部一體連接於拇指固定部與基部之間,且虎口支撐部具有一支撐塊。固定帶組設於本體,用以將本體固定於手掌。藉此,拇指可獲得有效的支撐與固定,更可改善使用者在配戴拇指固定器時的悶熱與不透氣等不適的感覺。100‧‧‧拇指固定器200‧‧‧本體210‧‧‧基部220‧‧‧手掌支撐部230‧‧‧魚際支撐部231‧‧‧開口240‧‧‧拇指固定部250‧‧‧虎口支撐部251‧‧‧支撐塊260‧‧‧穿孔300‧‧‧固定帶310‧‧‧接合件
