08-12 micron has been reported by Asad et. al. using hybrid-EDM process

Asad ABMA, Masaki T, Rahman M, Lim HS, Wong YS (2007) Tool-based micromachining. J Mater Process Technol 192–193:204–211

So simple is not the answer, because it is now a question of what technical equipments are aveailable to me and what price I will pay for it. Another important question is how deep I want to make this hole and which material is to machining.

Best regards

Hans-Peter

Agree with Dr. Schulze.

However, i wish to add that rather than simply asking for minimum diameter of hole that can be drilled using EDM, i request you to specify the application.

Because what is not possible may become possible tomorrow.

Regards,

@ H.P. Schulze and Janak Valaki Sirs

Thanks for your reply.

My question was with reference  to the definition of micro level hole that could be drilled using EDM process.

I referred various books and papers however the definition of minimum size hole was varying in each.