Fixing device and image forming apparatus which utilizes a nip supporting member to support a nip forming member

A fixing device comprising:

• an endless fixing belt;
• a fixing belt holder that holds the fixing belt;
• a pressure member to contact an outer portion of the fixing belt;
• a nip forming member that is disposed inside the fixing belt and forms a nip by supporting the fixing belt, the fixing belt being between the nip forming member and the pressure member;
• a nip supporting member that supports the nip forming member;
• a side plate that supports the fixing belt holder and the nip supporting member;
• and
• a pressure mechanism that presses the pressure member against the fixing belt and towards the nip forming member,
• wherein the nip supporting member includes a first element and a second element which is substantially perpendicular to the first element, a first end of the first element protruding though the second element, the first end of the first element directly supporting the nip forming member and a second end of the first element which is opposite to the first end of the first element being supported by the side plate.