LED light source lamp having drive circuit arranged in outer periphery of LED light source

An LED light source lamp configured to be used by being attached to a lamp holder, the LED light source lamp comprising:

• a housing configured to be attached to the lamp holder;
• an LED module provided in the housing;
• a drive circuit provided in the housing and configured to drive the LED module to cause the LED module to emit light;
• an LED installation plate on which the LED module is installed;
• a cover arranged so as to block an optical axis of the LED module and configured to transmit light emitted from the LED module;
• and
• a separation member configured to separate the drive circuit from a space between the LED module and the cover in the housing, wherein
• the LED installation plate has a rear surface, opposite the surface on which the LED module is installed, the rear surface being configured to closely contact the lamp holder, and comprising a part of the housing.