Fixed bed reactor

The present invention provides a fixed bed reactor comprising: a pipe for introducing a gas-liquid two-phase flow from the upper part of the fixed bed reactor into the interior thereof; and an inlet baffle plate which is disposed inside the fixed-bed reactor so as to face the introduction port of the pipe, the inlet baffle plate being a horizontally disposed flat plate, the introduction port of the pipe being disposed directly above the center position of the inlet baffle plate, and a shielding part standing upward on the main surface of the inlet baffle plate, and a shielding portion disposed radially outward of a position where the outer diameter of the introduction port of the duct is projected onto the inlet flap, the shielding portion having a shielding surface that faces the center position side and that suppresses the dispersion of the gas-liquid two-phase flow toward the outer diameter side of the inlet flap, the shielding portion being disposed radially outward of the position where the outer diamete