A reaction apparatus for producing trichlorosilane in which metal silicon powder M is reacted with hydrogen chloride gas, thus generating trichlorosilane, includes: an apparatus body into which the metal silicon powder is supplied; and an ejection port for ejecting the hydrogen chloride gas into the apparatus body from the bottom part of the apparatus body, wherein a plurality of holed pieces having a through hole penetrating in the thickness direction and a plurality of pellets interposed between these holed pieces are stacked in a mixed state on the upper side of the ejection port.