Particulate sensor

A particulate sensor attached to a metal gas flow pipe through which a target gas containing particulates flows and which is maintained at a ground potential, said particulate sensor comprising:

• an inner metallic member which is maintained at a first potential different from the ground potential and which has a gas introduction pipe into which the target gas is introduced;
• a tubular outer metallic member which surrounds a radially outer circumference of the inner metallic member and which is attached to the gas flow pipe to thereby be maintained at the ground potential;
• and
• a tubular insulating spacer which is interposed between the inner metallic member and the outer metallic member so as to electrically insulate them from each other and which has a tubular gas contact portion being exposed to the interior of the gas flow pipe and contacting the target gas flowing through the gas flow pipe, wherein
• the insulating spacer has a heater that heats the gas contact portion, a tubular spacer main body formed of an insulating ceramic, and a laminar heater section covering an outer circumferential surface of the spacer main body and including the heater,
• the heater includes a heat generation resistor embedded in the insulating spacer, and
• the laminar heater section includes a laminar heat generation resistor extending in the circumferential direction of the insulating spacer and also includes a cover insulating layer which is formed of an insulating ceramic and covers the laminar heat generation resistor, wherein opposite end portions of the laminar heat generation resistor located on opposite sides in the circumferential direction are disposed to face each other in the circumferential direction and be close to each other.