A sample container for a fluorescent X-ray analyzer. The sample container includes a first receptacle that accommodates a liquid sample and has a first opening and a second opening; an analytical film that closes off the first opening and transmits X-rays; a protective receptacle that includes a protective film for transmitting X-rays and covers the analytical film; and a pressure adjustment valve that adjusts a pressure inside the first receptacle. The first receptacle has a first space facing the first opening, a second space facing the second opening, and a connection hole connecting the first space and the second space. A cross-sectional area of the connection hole is smaller than an area of the first opening.