An object of the present invention is to provide a compound and a pharmaceutical composition which exhibit strong antibacterial activity against Gram-negative bacteria and drug-resistant Gram-negative bacteria. According to the present invention, a compound represented by General Formula [1] (the reference signs in the formula have the same definitions as those described in the present specification) or a salt thereof has strong antibacterial activity against Gram-negative bacteria such as Pseudomonas aeruginosa and drug-resistant Gram-negative bacteria including multidrug-resistant Pseudomonas aeruginosa, and the pharmaceutical composition containing the compound or a salt thereof is useful as an antibacterial agent.s
