A fluid chip suitable for a fluid device is disclosed in which an upper surface of a flow passage has another member bonded thereto. The disclosed fluid chip, in which a flow passage is formed, comprises a base material having a top surface forming at least a portion of a bottom surface of a flow passage, and a bonding member which is formed from an elastomer resin and an upper end surface of which is provided in a position higher than the top surface of the base material. The base material has a support post portion which projects from the top surface and defines the height of a side surface of the flow passage, and the support post portion of the base material is embedded in the bonding member.