An Electrospray probe which includes a replaceable or disposable micron size diameter Electrospray tip used for low flow rate Electrospray has been developed. The Electrospray probe assembly combines the use of a low pressure gas and electric fields to initiate and sustain the Electrospray process at low liquid flow rates. The operational flow rates of this probe range from below 25 nL/min to over 1 .mu.L/min, with total sample volume loaded ranging from less than 1 .mu.L to over 20 .mu.L. The Electrospray probe assembly includes axial and radial adjustment of the Electrospray tip position relative to the sampling orifice into vacuum and that tip position can be locked in place. The replaceable microtip can be safely removed from the Electrospray (ES) chamber without turning off high voltage within the ES chamber. Telescoping support ways have been included to prevent ES tip damage by guiding the Electrospray probe tip during removal from and insertion into the ES chamber. The replaceable microtip is held in a fixed position during operation with a collet assembly which also provides electrical contact with coated microtips. The replaceable microtip ES probe assembly is compatible with microtips that are metal or coated or uncoated glass materials. For uncoated glass microtips the ES probe assembly accommodates a wire electrical contact which is installed in the replaceable microtip bore.