A flow-rate control system for controlling a minute flow rate of a liquid flowing through a fluid channel having an outlet environment of constant pressure, the flow-rate control system comprising: a flow-rate control valve; a pressure detection part for detecting the pressure of the fluid in the fluid channel; a pressure/flow-rate conversion part for calculating a flow rate from a fluid pressure detected at the pressure detection part; and a block-shaped body, one surface of which is provided with the flow-rate control valve and the pressure detection part, and inside of which is provided a connecting fluid channel connecting the flow-rate control valve and the pressure detection part; wherein the connecting fluid channel includes a first inclined channel gradually inclined to an area in which the pressure detection part is provided, as the first inclined channel is inclined from an area of said surface of the block-shaped body where the flow-rate control valve is provided to the inside of the block-shaped body, and a second inclined channel gradually inclined to an area in which the flow-rate control valve is provided, as the second inclined channel is inclined from an area of said surface of the block-shaped body where the pressure detection part is provided to the inside of the block-shaped body, the second inclined channel being connected to an end of the first inclined channel. a flow-rate control valve; a pressure detection part for detecting the pressure of the fluid in the fluid channel; a pressure/flow-rate conversion part for calculating a flow rate from a fluid pressure detected at the pressure detection part; and a block-shaped body, one surface of which is provided with the flow-rate control valve and the pressure detection part, and inside of which is provided a connecting fluid channel connecting the flow-rate control valve and the pressure detection part; wherein the connecting fluid channel includes a first inclined channel gradually inclined to an area in which the pressure detection part is provided, as the first inclined channel is inclined from an area of said surface of the block-shaped body where the flow-rate control valve is provided to the inside of the block-shaped body, and a second inclined channel gradually inclined to an area in which the flow-rate control valve is provided, as the second inclined channel is inclined from an area of said surface of the block-shaped body where the pressure detection part is provided to the inside of the block-shaped body, the second inclined channel being connected to an end of the first inclined channel. a first inclined channel gradually inclined to an area in which the pressure detection part is provided, as the first inclined channel is inclined from an area of said surface of the block-shaped body where the flow-rate control valve is provided to the inside of the block-shaped body, and a second inclined channel gradually inclined to an area in which the flow-rate control valve is provided, as the second inclined channel is inclined from an area of said surface of the block-shaped body where the pressure detection part is provided to the inside of the block-shaped body, the second inclined channel being connected to an end of the first inclined channel.