PURPOSE: To optionally rewrite weight without using a storage means by connecting neurons through an EEPROM and expressing the connection load between the neurons by the quantity of charge accumulated in the trap of the EEPROM or the quantity of charge accumulated in a floating gate.

CONSTITUTION: A weighting voltage generating circuit 1 generates voltages V1 to Vn based upon a learning result outputted from a learning computing element 2, and in the case of impressing these voltages V1 to Vn to connection parts I1 to In, for instance, the voltage V1 is impressed between the gates and drains of the EEPROMs T1, T2 in the connection part I1 respectively through terminals P1, P2 (P1', P2') and the voltage V1 is used as a writing voltage to the EEPROMs T1, T2. Thereby, the threshold voltage Vth of the EEPROMs T1, T2 is set up to a value corresponding to the V1 (i.e. weight) and held. There by, coupling charge between the preceding neuro element for outputting x1 and the shown neuro element can be self-memorably set up. Thereby, the use of a storage means can be omitted.