Chemical synthesis device and method for manufacturing chemical synthesis device

A method for manufacturing a chemical synthesis device having a first channel in which a plurality of fluids are subjected to chemical synthesis, the method comprising:

• forming a pre-patterned layer and a side wall layer on a first substrate;
• forming, in the pre-patterned layer, a first through hole and a second through hole that penetrate the pre-patterned layer;
• forming a first protective film on a surface of the pre-patterned layer that remains after forming the first through hole and the second through hole and on an exposed surface of the first substrate;
• and
• attaching a surface of a second substrate provided with a second protective film on the second protective film side to a surface of the first substrate on the first protective film side,
• wherein the side wall layer is provided with a first through hole and a second through hole,
• the first through hole forms a portion of the first channel,
• at least a portion of the second through hole forms a portion of a second channel that is formed along the first channel and that is different from the first channel, and
• a medium for controlling a temperature of the fluids flowing through the first channel flows through the second channel.