A functional device for chemistry, biology, energy using chemical and physical properties of a micro/nano-channel, comprising: a first substrate which has a groove formed on one surface of the first substrate; a second substrate which is integrally disposed with the first substrate by bonding one surface of the second substrate and the one surface of the first substrate, and forms a flow path together with the groove of the first substrate; and at least one modification object chosen within the list consisting of a capture body which captures a target substance supplied into the flow path, an electrode which imparts an electrical or a chemical action to the target substance, and a catalyst, in which the modification object is disposed by being modified on a part of an inner surface of the flow path, wherein each of the first substrate and the second substrate is a glass substrate, characterized in that a bonding portion between the one surface of the first substrate and the one surface of the second substrate has a fluorine concentration of greater than or equal to 0.6 at% and less than or equal to 3.5 at% as measured by peeling off the bonded first and second substrates (2, 6) and measuring the fluorine concentration of the bonding portion thus exposed, and the bonding portion between the one surface of the first substrate and the one surface of the second substrate includes a F-Si bond in which fluorine is bonded to silica included in at least one substrate (2,6), the presence of the F-Si bond being derived from a peak strength of energy measured by a photoelectric spectroscopy of the bonding portion, and the flow path is a fine flow path of a microscale or a nanoscale. a first substrate which has a groove formed on one surface of the first substrate; a second substrate which is integrally disposed with the first substrate by bonding one surface of the second substrate and the one surface of the first substrate, and forms a flow path together with the groove of the first substrate; and at least one modification object chosen within the list consisting of a capture body which captures a target substance supplied into the flow path, an electrode which imparts an electrical or a chemical action to the target substance, and a catalyst, in which the modification object is disposed by being modified on a part of an inner surface of the flow path, wherein each of the first substrate and the second substrate is a glass substrate, characterized in that a bonding portion between the one surface of the first substrate and the one surface of the second substrate has a fluorine concentration of greater than or equal to 0.6 at% and less than or equal to 3.5 at% as measured by peeling off the bonded first and second substrates (2, 6) and measuring the fluorine concentration of the bonding portion thus exposed, and the bonding portion between the one surface of the first substrate and the one surface of the second substrate includes a F-Si bond in which fluorine is bonded to silica included in at least one substrate (2,6), the presence of the F-Si bond being derived from a peak strength of energy measured by a photoelectric spectroscopy of the bonding portion, and the flow path is a fine flow path of a microscale or a nanoscale.