Polishing liquid and chemical mechanical polishing method

A polishing liquid used for chemical mechanical polishing of an object to be polished having a cobalt-containing film, the polishing liquid comprising:

• colloidal silica;
• an organic acid;
• a nitrogen-containing aromatic heterocyclic compound which is one or more selected from the group consisting of a compound represented by General Formula (I), a compound represented by General Formula (II), a compound represented by General Formula (III), a compound represented by General Formula (IV), and a compound represented by General Formula (V), and has a C log P value of less than 1.0;
• and
• hydrogen peroxide,
• wherein a pH is 8.5 to 12.0,
• in General Formula (I), R11 and R12 each independently represent a hydrogen atom, a hydrophilic group, or a hydrocarbon group having a hydrophilic group, and R11 and R12 may be bonded to each other to form a ring,
• in General Formula (II), a ring A2 represents a benzene ring or a 6-membered aromatic heterocycle, R21 represents a hydrophilic group or a hydrocarbon group having a hydrophilic group, and R22 represents a hydrogen atom, a hydrophilic group, or a hydrocarbon group having a hydrophilic group,
• in General Formula (III), a ring A3 represents a benzene ring or a 6-membered aromatic heterocycle, R31 represents a hydrophilic group or a hydrocarbon group having a hydrophilic group, and R32 represents a hydrogen atom, a hydrophilic group, or a hydrocarbon group having a hydrophilic group,
• in General Formula (IV), R41 represents a substituent, R42 represents a hydrogen atom, a hydrophilic group, or a hydrocarbon group having a hydrophilic group, and R41 and R42 may be bonded to each other to form a ring,
• in General Formula (V), R51, R52, and R53 each independently represent a hydrogen atom, a hydrophilic group, or a hydrocarbon group having a hydrophilic group, and R51 and R52 may be bonded to each other to form a ring, and R51 and R53 may be bonded to each other to form a ring.