A fine work assistance system comprising a master-slave manipulator, in which a slave unit performs a predetermined operation for fine work on a work object in response to input of a user operation to a master unit of the manipulator, the fine work assistance system comprising: an imaging unit that captures an image of the work object; and a display unit that enlarges the work object image captured by the imaging unit and displays the enlarged image to be visible to a user, wherein the slave unit has a parallel link mechanism with at least 3 degrees of freedom, the parallel link mechanism including a base that is supported in a predetermined location in a space where the work object is present, an end effector that handles the work object or a work instrument, and a plurality of links that are disposed in parallel between the base and the end effector, the parallel link mechanism being capable of changing a position and orientation of the end effector in a predetermined range relative to the base, wherein the parallel link mechanism includes a plurality of linear actuators supported by the base, and linearly moves one end of each link using the linear actuators to move the end effector connected to the other end of each link, the end effector includes a tip operation part that handles the work object or the work instrument in a motion with at least 1 degree of freedom, the motion being different from an overall motion of the end effector by the parallel link mechanism, and a hydraulic driving mechanism that produces the motion of the tip operation part for handling the work object or the work instrument, the master unit includes an operation input unit that receives a user operation, and a support mechanism unit that is capable of acquiring information on a position and orientation of the operation input unit using a plurality of sensors while movably supporting the operation input unit with the same degree of freedom as the parallel link mechanism, the operation input unit has an input mechanism that changes a fluid pressure of hydraulic fluid in response to a predetermined user operation independent of an operation for moving the whole of the operation input unit, the input mechanism being connected to the hydraulic driving mechanism in the end effector of the slave unit so as to pass the hydraulic fluid through a pipe, the input mechanism being further provided with a pair of levers parts provided at two points opposed to each other on the outer surface of the operation input unit, as an input part for a direct operation with at least two fingers of the user, such that an input operation to the input part with the at least two fingers corresponds to a direct manual operation of an operating part in the tip operation part of the end effector, and the hydraulic driving mechanism activates the tip operation part in response to a change of a fluid pressure of hydraulic fluid by a user operation on the input mechanism in the operation input unit. an imaging unit that captures an image of the work object; and a display unit that enlarges the work object image captured by the imaging unit and displays the enlarged image to be visible to a user, wherein the slave unit has a parallel link mechanism with at least 3 degrees of freedom, the parallel link mechanism including a base that is supported in a predetermined location in a space where the work object is present, an end effector that handles the work object or a work instrument, and a plurality of links that are disposed in parallel between the base and the end effector, the parallel link mechanism being capable of changing a position and orientation of the end effector in a predetermined range relative to the base, wherein the parallel link mechanism includes a plurality of linear actuators supported by the base, and linearly moves one end of each link using the linear actuators to move the end effector connected to the other end of each link, the end effector includes a tip operation part that handles the work object or the work instrument in a motion with at least 1 degree of freedom, the motion being different from an overall motion of the end effector by the parallel link mechanism, and a hydraulic driving mechanism that produces the motion of the tip operation part for handling the work object or the work instrument, the master unit includes an operation input unit that receives a user operation, and a support mechanism unit that is capable of acquiring information on a position and orientation of the operation input unit using a plurality of sensors while movably supporting the operation input unit with the same degree of freedom as the parallel link mechanism, the operation input unit has an input mechanism that changes a fluid pressure of hydraulic fluid in response to a predetermined user operation independent of an operation for moving the whole of the operation input unit, the input mechanism being connected to the hydraulic driving mechanism in the end effector of the slave unit so as to pass the hydraulic fluid through a pipe, the input mechanism being further provided with a pair of levers parts provided at two points opposed to each other on the outer surface of the operation input unit, as an input part for a direct operation with at least two fingers of the user, such that an input operation to the input part with the at least two fingers corresponds to a direct manual operation of an operating part in the tip operation part of the end effector, and the hydraulic driving mechanism activates the tip operation part in response to a change of a fluid pressure of hydraulic fluid by a user operation on the input mechanism in the operation input unit.