A fuel processor comprising: a reforming part provided around a heating unit including a burner and adapted to generate hydrogen containing gas composed of carbon monoxide and water; a converting part provided around the heating unit and adapted to generate hydrogen containing gas composed of low-concentration carbon monoxide by reacting carbon monoxide and water in the hydrogen containing gas generated in the reforming part; a mixing part provided around the heating unit and adapted to mix air supplied from an air inlet port and the hydrogen containing gas generated in the converting part; and a CO removing part adapted to react oxygen, carbon monoxide in the gas supplied from the mixing part, and a CO removal catalyst to generate hydrogen containing gas hardly containing carbon monoxide, characterized in that the fuel processor further comprises a partition plate dividing a passage of the mixing part, the partition plate partially including a tilted portion, wherein the mixing part is formed between a first partition near the converting part and a second partition, near the CO removing part, and a relationship is established below: L1 ≠ L2 where L1 is a distance from the heating unit to a first contact portion, the first contact portion providing a contact between the partition plate and one of the first and second partitions (21, 22), and L2 is a distance from the heating unit to a second contact portion, the second contact portion providing a contact between the partition plate and the other of the first and second partitions (21, 22). a reforming part provided around a heating unit including a burner and adapted to generate hydrogen containing gas composed of carbon monoxide and water; a converting part provided around the heating unit and adapted to generate hydrogen containing gas composed of low-concentration carbon monoxide by reacting carbon monoxide and water in the hydrogen containing gas generated in the reforming part; a mixing part provided around the heating unit and adapted to mix air supplied from an air inlet port and the hydrogen containing gas generated in the converting part; and a CO removing part adapted to react oxygen, carbon monoxide in the gas supplied from the mixing part, and a CO removal catalyst to generate hydrogen containing gas hardly containing carbon monoxide, characterized in that the fuel processor further comprises a partition plate dividing a passage of the mixing part, the partition plate partially including a tilted portion, wherein the mixing part is formed between a first partition near the converting part and a second partition, near the CO removing part, and a relationship is established below: L1 ≠ L2 where L1 is a distance from the heating unit to a first contact portion, the first contact portion providing a contact between the partition plate and one of the first and second partitions (21, 22), and L2 is a distance from the heating unit to a second contact portion, the second contact portion providing a contact between the partition plate and the other of the first and second partitions (21, 22). where L1 is a distance from the heating unit to a first contact portion, the first contact portion providing a contact between the partition plate and one of the first and second partitions (21, 22), and L2 is a distance from the heating unit to a second contact portion, the second contact portion providing a contact between the partition plate and the other of the first and second partitions (21, 22).