There is provided a fluid control apparatus which can reduce the number of members and can improve the assembling operation efficiency.A pressure indication device 4 to be replaced with a relatively-higher frequency is coupled to a base block 5 existing thereunder through male screw members 17 from above. An on-off valve 6 to be replaced with a relatively-lower frequency has, at its lower portion, a block-shaped main body 6a formed integrally therewith. The main body 6a of the on-off valve 6 is coupled to the base block 5 through male screw members 18 in the forward and rearward directions.