Pyroelectric infrared sensor device

A pyroelectric infrared sensor device comprising:

• a pyroelectric infrared sensor part;
• and
• a cover member, wherein
• the pyroelectric infrared sensor part comprises:
• a pyroelectric element;
• a housing that the pyroelectric element is placed inside of and comprises an opening at a position facing a light receiving surface of the pyroelectric element;
• and
• an infrared transmission filter that is located to cover the opening of the housing,
• the cover member covers at least a top surface of the pyroelectric infrared sensor part in a place where the cover member faces the infrared transmission filter of the pyroelectric infrared sensor part,
• the infrared transmission filter has a property to transmit light equal to or greater than a wavelength of 1 μm, and
• the cover member has a property that a transmittance of infrared light having a wavelength of from 3 μm to 5.5 μm is equal to or greater than 10% and has a uniform material quality in an area corresponding to the top surface of the pyroelectric infrared sensor part.