We introduce a secure architecture called an attested meter for advanced metering that supports large-scale deployments, flexible configurations, and enhanced protection for consumer privacy and metering integrity. Our study starts with a threat analysis for advanced metering networks and formulates protection requirements for those threats. The attested meter satisfies these through a unified set of system interfaces based on virtual machines and attestation for the software agents of various parties that use the meter. We argue that this combination provides a well-adapted architecture for advanced metering and we take a step towards demonstrating its feasibility with a prototype implementation based on the Trusted Platform Module (TPM) and Xen Virtual Machine Monitor (VMM). This is the first effort to use virtual machines and attestation in an advanced meter.