This paper provides novel methods for inference in a very general class of ill-posed models in econometrics, encompassing the nonparametric instrumental regression, different functional regressions, and the deconvolution. I focus on uniform confidence sets for the parameter of interest estimated with Tikhonov regularization, as in Darolles, Fan, Florens, and Renault (2011). I first show that it is not possible to develop inferential methods directly based on the uniform central limit theorem. To circumvent this difficulty I develop two approaches that lead to valid confidence sets. I characterize expected diameters and coverage errors uniformly over a large class of models (i.e. constructed confidence sets are honest). Finally, I illustrate that introduced confidence sets have reasonable width and coverage properties in samples commonly used in applications with Monte Carlo simulations and considering application to Engel curves. ′ 1, . On the other hand, the process 2, is assumed not to change with . Since stochastic processes ′ 1, and 2, may be not readily available, we denote by^′ 1, and^2 , their respective consistent estimators and by^1 = max 1≤ ≤ ‖^′ 1, ‖ and^2 = max 1≤ ≤ ‖^2 , ‖ ∞ the corresponding estimators of their envelops. Finally, for some i.i.d. sequence of Rademacher random variables ( ) =1 , independent 7 The rigorous study of bootstrap properties is beyond the scope of this paper and is left for future research.