Image sensor element and image sensor

An image sensor element includes a transfer transistor TX, a LOFIC select transistor LF, a photodiode PD, and a first overflow path OFP. The transfer transistor TX outputs a readout signal from a first end. The LOFIC select transistor LF includes a first end connected to a second end of the transfer transistor TX, and a second end connected to a capacitor. The photodiode PD is connected in common to a third end of the transfer transistor and a third end of the LOFIC select transistor LF. The first overflow path OFP is formed between the photodiode PD and a second end of the LOFIC select transistor LF. Each of the transfer transistor TX and the LOFIC select transistor LF is configured with a vertical gate transistor.