A gas trapping member provided according to a specific example of the present invention is used in a medicinal solution injection device. The medicinal solution injection device includes a gas generating space inside, and injects the medicinal liquid by a gas pressure generated in the gas generating space. A gas trapping member provided according to a specific example of the present invention includes: a first film composed of a material that can pass through a gas generated in a gas generation space and cannot pass through a liquid substance used to generate the gas； a second film, It is bonded to the first film to form a closed gas trapping space, and is composed of a material that cannot pass through the gas generated in the gas generating space and the liquid substance used to generate the gas； and a gas trapping tube that makes the above The gas trapping space communicates with the outside of the gas generation space, and guides the gas trapped in the gas trapping space to the outside of the gas generation space.根據本發明的一具體例提供的氣體捕集部件用於藥液注入裝置，該藥液注入裝置在內部包括氣體產生空間，並且通過在上述氣體產生空間內產生的氣體壓力來注入藥液。根據本發明的一具體例提供的氣體捕集部件包括：第一膜，其由在氣體產生空間內產生的氣體能夠通過、並且用於產生氣體的液體物質無法通過的材質構成；第二膜，其與上述第一膜接合而形成密閉的氣體捕集空間，並且由在上述氣體產生空間內產生的氣體以及用於產生氣體的液體物質無法通過的材質構成；以及氣體捕集管，其使上述氣體捕集空間和上述氣體產生空間的外部連通，並且將被捕集到上述氣體捕集空間的氣體引導至上述氣體產生空間的外部。
