Recording element substrate and recording device

A recording element substrate comprising:

• a discharging port array which is disposed on a front surface of the recording element substrate, and includes a plurality of discharging ports arrayed in an array direction;
• a plurality of nozzles which extend in a direction intersecting with the front surface of the recording element substrate, and are connected to the plurality of discharging ports, respectively;
• a passage forming portion in which a plurality of individual passages and a common passage are formed, the plurality of individual passages extending in a direction along the front surface of the recording element substrate and being connected to the plurality of nozzles, respectively, and the common passage being connected to the plurality of individual passages;
• a plurality of supply ports which are disposed on the common passage and are arrayed along the array direction, and are disposed such that, in a case where the plurality of nozzles are divided into a plurality of nozzle groups and each nozzle group includes one or a plurality of nozzles, the plurality of supply ports are disposed at positions corresponding to the plurality of nozzle groups on the common passage, respectively;
• and
• a plurality of supply passages which extend from the plurality of supply ports to a rear surface of the recording element substrate in a direction intersecting with the rear surface of the recording element substrate, wherein
• a plurality of heaters configured to heat liquid flowing through the common passage are provided for each of the plurality of supply ports along at least a part of a peripheral edge of the supply port.