The objective of MARKET4.0 is to define, develop and validate an open multi-sided marketplace, based on a trusted P2P data sharing infrastructure for Industry 4.0, that brings together Industrial Product Service Systems (IPSS) providers (supply side) and OEMs as their customers (demand side). It will allow direct interaction among the different sides to improve the sales power of production equipment SMEs. MARKET4.0 will offer advanced web-presence of production equipment SMEs extended by functionalities such as simulations, VR/AR capabilities and a P2P (Industrial Data Space) offering smart user-services and a secure API to try and test the Digital Twin of the production equipment, on top supplier and customer data. This will facilitate direct transactions between market peers (supplier-to-supplier, supplier-to-customer, customer-to-suppliers and more) during the entire B2B lifecycle, i.e. from equipment search to procurement and commissioning. MARKET4.0 will create trust in the business transactions between SME production equipment manufacturers and their customers, as an integral element of the Industrial Data Space (IDS) reference architecture. It includes technological trust (simulation before purchasing), financial trust (Blockchain distributed ledger technology for secure payment), delivery and (anonymized) feedback. In MARKET4.0 the supply side (mainly SMEs) may offer a) production equipment, b) services that extend the capabilities of the production equipment, c) production equipment as a service and d) collaborative engineering services. The marketplace will generate additional value by providing engineering services and acting as a mediator between suppliers and customers.