Electrostatic discharge protection circuit and semiconductor circuit device

An electrostatic discharge protection circuit comprising:

• a first line having a first potential;
• a second line having a second potential that is different from the first potential;
• a trigger circuit connected between the first line and the second line;
• and
• a discharge circuit including a field effect transistor that is connected between the first line and the second line, whose gate is directly or indirectly connected to a predetermined connection node of the trigger circuit, and that conducts electricity by a change in a potential of the gate,
• wherein the trigger circuit includes a first circuit and a second circuit that are connected in parallel,
• the first circuit includes:
• a first impedance element on the first line side and a capacitor element on the second line side that are connected in series between the first line and the second line;
• and
• a first transistor of first conductivity type that is connected in series to the first impedance element and is connected in parallel to the capacitor element,
• the second circuit includes:
• a first transistor of second conductivity type on the first line side and a second impedance element on the second line side that are connected in series between the first line and the second line,
• a gate of the first transistor of second conductivity type is connected to a first node located between the first impedance element and the, capacitor element,
• a gate of the first transistor of first conductivity type is connected to a second node located between the first transistor of second conductivity type and the second impedance element, and
• the predetermined connection node is the first node or the second node.